solidThinking Inspire in the Design Process

Inspire is software tuned for design exploration during preliminary
stages of the development of a product. It enables designers to study
topological options using dimensional, loading, support, and material
properties. It does this without the hassle of complicated set-ups and the
expertise normally required for FEA (finite element analysis) studies (see
figure 1).

Inspire is stand-alone software from solidThinking. It has a basic
solid-geometry creation toolset and an optimization platform based on
OptiStruct, an optimization platform from the parent Altair. In this
article, I am going to look at how Inspire fits into the proverbial toolbelt
for engineers, architects, and product designers (see figure 2).

Figure
2: Inspire expanding the design exploration phase to include later
stages (indicated by red dotted lines) and reduce the number of
design iterations

Inspiring the Design Process

Fluidity is not a term used generously in the design process when
describing the contribution of MCAD software, and there are good reasons for
this: the steep learning curve of traditional MCAD software, its cost, and
the difficulty of such software to communicate with proprietary data formats
(i.e., translation errors).

In an age when pinch-to-zoom and voice interaction blurs human-to-machine
interaction, the user interface of most design software is still firmly
limited by dialog boxes and software frameworks developed and used by a
previous generation of software frameworks. It is no wonder many designers
prefer to perform their initial studies on paper. Although it is hard to
supplant the immediacy of pencil-on-paper for formal explorations,
subsequent iterations occur mostly in software for easier repetition and
communication.

Inspire enhances the design process in three ways: (a) through the user
interface, (b) by its ability to work with generic and industry-standard
data formats, and (c) with its fast, powerful optimization process. Let's
take a look at each of these.

Simplifying the User Interface

The toughest challenge when working with a UI (user interface) in
engineering design software is to find the location of all its tools. I
often find myself drowning in icons, sub-menus, and the ribbon's split
buttons. Most software developers design this kind of UI, unfortunately, and
the result is a long learning curve and lost productivity.

The hidden cost here is that of translation. Designers like to use paper,
and sometimes even easy-to-use software for quickly exploring forms and
ideas. As a designer myself, my first instinct is to confirm the design's
viability as quickly as possible on paper, or the software of my choice.
Ultimately, I need to record the designs in a more widely used format for
analysis, be it spatial, structural, or thermal.

The point here is that every change in format requires translation and
the accompanying loss of data. One of the ways that Inspire eases
translation costs is by shortening the learning curve. It does this by
making it easy to move models in and out of the software, and by making it
easy to create geometry within the application. It's not necessarily
innovative, but solidThinking had the idea of creating an interface with
just four menus, along with tools that are hierarchically bunched together
on an uncluttered screen. For users more familiar with traditional MCAD
applications, this is simply mind-blowing (see figure 3).

Figure
3: The simple UI of Inspire; the inset shows how tools are grouped
around a common theme, and are visible only on mouse hover

The only other interface where I have seen such thoughtful design is in
games, navigation software, and Web and phone apps. Rather than using the UI
as a technical layer between the designer and the idea, Inspire's interface
is an extension of the designer's thought framework.

Software Interoperability

With MCAD applications increasingly converging in terms of features and
target industries, interoperability is a term widely abused by marketing.
Software makers realize that in their fragmented market, everyone has to
play nice. The caveats relating to functional inadequacies of
interoperability are, however, usually hidden or - worse still - discovered
at an inopportune stage of design development.

From this perspective, Inspire is very straight-forward: it accepts 3D
solid objects created in the popular industry-standard formats, because it
needs only the 3D volume of the model. This is called its "Design Space,"
within which we can perform formal explorations. To explore formal
variations, for example, I trace the parts I want to optimize, and then add
material descriptors, loads, and constraints.

Note that Inspire is available in both PC Windows and Mac OS X versions,
making it less of a headache when it comes to managing IT ecosystems.

Inspire and 3D printing

3D printing is not a recent development, but now is quickly becoming a
staple within the design process. Inspire requires solids as input for its
optimization; coincidentally, 3D printing also prefers solids (or
water-tight surfaces). In this sense, models generated in Inspire are almost
always print-ready.

(3D printing is usually not as simple as hitting the Print button.
Limitations in the strength of the print medium, such as powder or plastic,
determine the smallest load-bearing component that can be printed without
the object crumbling under its own weight. The problem with models not made
of 3D solids, such as those made from 3D surfaces, is that these models tend
to have miniscule gaps that increase the likelihood of print failure.)

Inspire's Role of Topological Optimization in Form-seeking

Aside from material characteristics, the geometry of the engineered form
determines many of its functional characteristics, such as cost, type of
manufacturing processes, and the operational life of the finished product.
While most forms seem intuitive or deductive, complex interaction of forces
and constraints are hard to deduce with certainty.

Topological optimization is the defining feature of Inspire. The
optimization can be performed using two basic criteria: maximum strength and
minimum mass. When these two criteria are combined with more sophisticated
constraints, such as material thickness, natural frequencies, gravity,
forces and constraints, then it becomes possible to develop an extended
range of forms and solutions that previously were too time consuming to
attain.

Many of the publicity images made with Inspire show morpho-genic
(biologically-inspired) outcomes.

Without such an exploration in the initial phase, designers would
otherwise have to wait until later in the product development cycle (such as
during analysis) to find out whether the designed form is best suited its
purpose.

Figures 4 and 5 show the first two versions of a humble wall shelf
bracket I designed. I designed the bracket with of different materials, one
aluminum and the other common ABS plastic. The support is constrained by two
pins connected to a backplate, which is then attached to a wall.

Figure
5: Same bracket take on different shape if made with ABS plastic

Figure 6 shows the result after the load is doubled on the bracket, but
with a uniformly distributed support provided by the backplate.

Figure
6: Bracket with a uniformly distributed back support, and without
the two pin supports

Caveats

Like many software tools, Inspire is based on a mature technology yet has
room for improvement. For instance, topological optimization is most
successful with isotropic materials, ones that have the same properties
throughout. This is not really a limitation of the software, but of the
technique itself, because materials are defined by Inspire in terms only of
their Young's modulus, Poisson ratio, density, and yield stress. This
uniformity works fine for many plastics and metals, but not for brittle,
reinforced, or directional materials, and so those materials are not
particularly suitable for optimization.

The default library provided with Inspire consists of a variety of steel,
aluminum, titanium, and plastics. Orthotropic materials (such as wood) and
reinforced one (such as composites and concrete) require analysis methods
that are unavailable within Inspire.

Secondly, Inspire cannot create complex forms based on splines or NURB
surfaces. It works only with 3D solids. While performing tests using 3D
solids generated with a 3rd party CAD program and exported to the *.stl file
format, I found that Inspire can easily import the geometry, but I have to
trace the 3D form using Inspire's solid-creation tools to perform
optimization.

Results shown have non-smooth surfaces which may be a result of limiting
the number of iterations done by the program. The assumption is that enough
iterations would result in a smooth surface in the examples used but
iterations were limited in this review in the interest of time.

Resulting shapes may be non-intuitive or unconventional. While Inspire
may create be a breakthrough design that was never before considered, I
suggest a healthy skepticism would be in order. Rather than accept the
results as unassailable, it wouldn't hurt to get a sanity check, such as a
rough calculation, a nod from an experienced analyst.

SolidThinking has a sister product called Evolve, which is designed for
building complex forms. Inspire can open models generated by Evolve, perform
optimizations, and then return the models.

Inspired Mass Customization

So what is the significance to a software tool like Inspire? Firstly,
innovative forms are no longer the exclusive domain of organizations with
resources to invest in fancy technology. We are in the midst of a
democratization of access to technology. With the advent of 3D printing and
just-in-time manufacturing, designs now require near-instant prototyping (or
pseudo-manufacturing) or at the very least very short manufacturing cycles.

Another paradigm shift affecting a large number of industries is the
seeming number of infinite customization options. In an age where the stroke
of the genius is quickly replaced by the ability to pick a winning mutation
from all the permutations generated by intelligent tools, software packages
like Inspire no longer are optional accessories; they are powerful weapons
for achieving much needed advantages over the competition.

Conclusion

solidThinking's Inspire is a tool designed to be part of a tool set,
rather than a standalone product for engineering design or analysis. With
its easy to use interface, Inspire is perfectly suited to the new generation
of design engineer (or even artist) that would like quick results with a
minimum of training. It suggests alternative shapes that may not have been
considered in a traditional design process. It facilitates 3D printing, a
technology that will let us create products we never knew could exist. From
this perspective, solidThinking Inspire is the right tool when introduced at
the best possible time.

Additional Information

About the Author

Francis Sebastian is an architect by training. He
teaches, supports and provide implementation services for
the AEC industry in the New York tri-state area and writes
for his para-analytics blog. More....